001: /*
002: * Copyright (c) 2003 The Visigoth Software Society. All rights
003: * reserved.
004: *
005: * Redistribution and use in source and binary forms, with or without
006: * modification, are permitted provided that the following conditions
007: * are met:
008: *
009: * 1. Redistributions of source code must retain the above copyright
010: * notice, this list of conditions and the following disclaimer.
011: *
012: * 2. Redistributions in binary form must reproduce the above copyright
013: * notice, this list of conditions and the following disclaimer in
014: * the documentation and/or other materials provided with the
015: * distribution.
016: *
017: * 3. The end-user documentation included with the redistribution, if
018: * any, must include the following acknowledgement:
019: * "This product includes software developed by the
020: * Visigoth Software Society (http://www.visigoths.org/)."
021: * Alternately, this acknowledgement may appear in the software itself,
022: * if and wherever such third-party acknowledgements normally appear.
023: *
024: * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
025: * project contributors may be used to endorse or promote products derived
026: * from this software without prior written permission. For written
027: * permission, please contact visigoths@visigoths.org.
028: *
029: * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
030: * nor may "FreeMarker" or "Visigoth" appear in their names
031: * without prior written permission of the Visigoth Software Society.
032: *
033: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
034: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
035: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
036: * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
037: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
038: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
039: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
040: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
041: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
042: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
043: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
044: * SUCH DAMAGE.
045: * ====================================================================
046: *
047: * This software consists of voluntary contributions made by many
048: * individuals on behalf of the Visigoth Software Society. For more
049: * information on the Visigoth Software Society, please see
050: * http://www.visigoths.org/
051: */
052:
053: package freemarker.template.utility;
054:
055: import java.util.ArrayList;
056: import java.util.HashMap;
057:
058: import freemarker.ext.util.WrapperTemplateModel;
059: import freemarker.template.AdapterTemplateModel;
060: import freemarker.template.TemplateBooleanModel;
061: import freemarker.template.TemplateCollectionModel;
062: import freemarker.template.TemplateDateModel;
063: import freemarker.template.TemplateHashModelEx;
064: import freemarker.template.TemplateModel;
065: import freemarker.template.TemplateModelException;
066: import freemarker.template.TemplateModelIterator;
067: import freemarker.template.TemplateNumberModel;
068: import freemarker.template.TemplateScalarModel;
069: import freemarker.template.TemplateSequenceModel;
070:
071: /**
072: * Utility methods for unwrapping {@link TemplateModel}-s.
073: * @author Attila Szegedi
074: * @version $Id: DeepUnwrap.java,v 1.6 2005/06/16 18:13:58 ddekany Exp $
075: */
076: public class DeepUnwrap {
077: private static final Class OBJECT_CLASS = Object.class;
078:
079: /**
080: * Unwraps {@link TemplateModel}-s recursively.
081: * The converting of the {@link TemplateModel} object happens with the following rules:
082: * <ol>
083: * <li>If the object implements {@link AdapterTemplateModel}, then the result
084: * of {@link AdapterTemplateModel#getAdaptedObject(Class)} for <tt>Object.class</tt> is returned.
085: * <li>If the object implements {@link WrapperTemplateModel}, then the result
086: * of {@link WrapperTemplateModel#getWrappedObject()} is returned.
087: * <li>If the object implements {@link TemplateScalarModel}, then the result
088: * of {@link TemplateScalarModel#getAsString()} is returned.
089: * <li>If the object implements {@link TemplateNumberModel}, then the result
090: * of {@link TemplateNumberModel#getAsNumber()} is returned.
091: * <li>If the object implements {@link TemplateDateModel}, then the result
092: * of {@link TemplateDateModel#getAsDate()} is returned.
093: * <li>If the object implements {@link TemplateBooleanModel}, then the result
094: * of {@link TemplateBooleanModel#getAsBoolean()} is returned.
095: * <li>If the object implements {@link TemplateSequenceModel} or
096: * {@link TemplateCollectionModel}, then a <code>java.util.ArrayList</code> is
097: * constructed from the subvariables, and each subvariable is unwrapped with
098: * the rules described here (recursive unwrapping).
099: * <li>If the object implements {@link TemplateHashModelEx}, then a
100: * <code>java.util.HashMap</code> is constructed from the subvariables, and each
101: * subvariable is unwrapped with the rules described here (recursive unwrapping).
102: * <li>Throw a <code>TemplateModelException</code>, because it doesn't know how to
103: * unwrapp the object.
104: * </ol>
105: */
106: public static Object unwrap(TemplateModel model)
107: throws TemplateModelException {
108: return unwrap(model, false);
109: }
110:
111: /**
112: * Same as {@link #unwrap(TemplateModel)}, but it doesn't throw exception if
113: * it doesn't know how to unwrap
114: * the object, but returns it as is.
115: */
116: public static Object premissiveUnwrap(TemplateModel model)
117: throws TemplateModelException {
118: return unwrap(model, true);
119: }
120:
121: private static Object unwrap(TemplateModel model, boolean permissive)
122: throws TemplateModelException {
123: if (model instanceof AdapterTemplateModel) {
124: return ((AdapterTemplateModel) model)
125: .getAdaptedObject(OBJECT_CLASS);
126: }
127: if (model instanceof WrapperTemplateModel) {
128: return ((WrapperTemplateModel) model).getWrappedObject();
129: }
130: if (model instanceof TemplateScalarModel) {
131: return ((TemplateScalarModel) model).getAsString();
132: }
133: if (model instanceof TemplateNumberModel) {
134: return ((TemplateNumberModel) model).getAsNumber();
135: }
136: if (model instanceof TemplateDateModel) {
137: return ((TemplateDateModel) model).getAsDate();
138: }
139: if (model instanceof TemplateBooleanModel) {
140: return ((TemplateBooleanModel) model).getAsBoolean() ? Boolean.TRUE
141: : Boolean.FALSE;
142: }
143: if (model instanceof TemplateSequenceModel) {
144: TemplateSequenceModel seq = (TemplateSequenceModel) model;
145: ArrayList list = new ArrayList(seq.size());
146: for (int i = 0; i < seq.size(); ++i) {
147: list.add(unwrap(seq.get(i)));
148: }
149: return list;
150: }
151: if (model instanceof TemplateCollectionModel) {
152: TemplateCollectionModel coll = (TemplateCollectionModel) model;
153: ArrayList list = new ArrayList();
154: TemplateModelIterator it = coll.iterator();
155: while (it.hasNext()) {
156: list.add(unwrap(it.next()));
157: }
158: return list;
159: }
160: if (model instanceof TemplateHashModelEx) {
161: TemplateHashModelEx hash = (TemplateHashModelEx) model;
162: HashMap map = new HashMap();
163: TemplateModelIterator keys = hash.keys().iterator();
164: while (keys.hasNext()) {
165: String key = (String) unwrap(keys.next());
166: map.put(key, unwrap(hash.get(key)));
167: }
168: return map;
169: }
170: if (permissive) {
171: return model;
172: }
173: throw new TemplateModelException(
174: "Cannot deep-unwrap model of type "
175: + model.getClass().getName());
176: }
177: }
|